Mine roof supports

ABSTRACT

A self-advancing mine roof support has a roof-engaging structure which includes an extendible and retractible extension bar or member. The roof-engaging structure carries a baffle plate and means is provided by which when the extension bar or member is retracted said baffle plate is automatically presented to the mined mineral, so as to limit the flushing of mineral towards the support, and when the extension bar or member is extended the baffle plate is automatically moved into an inoperative or stowed position in which it will not obstruct the passage of a mineral mining machine. In one preferred embodiment of the invention said means is a linkage arrangement pivotally connected between the baffle plate and a relatively stationary part of the roofengaging structure. Conveniently the baffle plate, when in its operative position, depends substantially vertically from the extension bar and when in its stowed position lies substantially horizontally under the extension bar.

[ June 17, 1975 [75] Inventor:

[ 1 MINE ROOF SUPPORTS Archelaius Dawson Allen, Leyland, England [73] Assignee: Gullick Dobson Limited, Lancashire,

England [22] Filed: Dec. 28, 1973 [21] Appl. No.: 429,674

[30] Foreign Application Priority Data Jan. 26, 1973 United Kingdom 3974/73 [52] US. Cl 61/45 D [51] Int. Cl. E2ld 15/44 [58] Field of Search 61/45 D, 63; 299/31, 33; 91/170 MP [56] References Cited UNITED STATES PATENTS 3,800,546 4/1974 Holken et a1. 61/45 D FOREIGN PATENTS OR APPLICATIONS 1,278,977 3/1968 Germany 61/45 D 1,800,846 6/1970 Germany 61/45 D 882,933 11/1961 United Kingdom... 61/45 D 924,372 4/1963 United Kingdom 61/45 D 1,037,734 8/1966 United Kingdom 61/45 D Primary Examiner-Dennis L. Taylor Attorney, Agent, or Firm-Berman, Bishoff & Platt 57 ABSTRACT A self-advancing mine roof support has a roofengaging structure which includes an extendible and retractible extension bar or member. The roofengaging structure carries a baffle plate and means is provided by which when the extension bar or member is retracted said baffle plate is automatically presented to the mined mineral, so as to limit the flushing of mineral towards the support, and when the extension bar or member is extended the baffle plate is automatically moved into an inoperative or stowed position in which it will not obstruct the passage of a mineral mining machine. In one preferred embodiment of the invention said means is a linkage arrangement pivotally connected between the baffle plate and a relatively stationary part of the roof-engaging Structure. Conveniently the baffle plate, when in its operative position, depends substantially vertically from the extension bar and when in its stowed position lies Substantially horizontally under the extension bar.

5 Claims, 2 Drawing Figures MINE ROOF SUPPORTS This invention is for improvements in or relating to mine 'roof supports.

The invention is particularly, although not exclusively concerned with self-advancing or powered mine roof supports of the kind comprising a base, one or more hydraulically extensible props or legs mounted on said base and a roof-engaging structure mounted on said prop'or props, the support also incorporating a pressure-fluid ram or device by which it is advanced as mining of mineral from the mineral face or excavation proceeds.

According to the present invention there is provided a mine roof support having a roof-engaging structure, an extension bar or member movable relatively to said roof-engaging structure for the extension thereof, a baffle carried by said roof-engaging structure and which it presents to the mined mineral. so as to limit the flushing of mineral towards the support, and means for automatically moving said baffle between an operative position when the extension bar is retracted and/or stowed, and an inoperative position when the extension bar is extended.

According to a still further feature of the invention there is provided a mine roof support having a roofengaging structure. an extension bar slidable in or on said roof-engaging structure, an anti-spalling plate or baffle pivoted to the forward end of said extension bar, for presentation thereby to the mineral face, and a link pivotally connected between said plate or baffle and a relatively stationary part of the support (e.g. the roofengaging structure) so that when the extension bar is retracted the baffle is in an operative position in which it depends substantially vertically from the extension bar, and when the extension bar is extended is moved to a stowed position in which it lies substantially hori zontally under the extension bar.

Conveniently the roof support includes or is adapted to work in association with a section of rail or the like for guiding or defining a track for a mineral mining ma chine in its passage along and into the mineral face and said section of rail includes an upstanding barrier the upper edge of which co-operates with the lower edge of said baffle or plate to limit the movement of spalling mineral towards the support. This barrier may be attached to the forward end of an advancing ram of the support. Alternatively or additionally a mineral gathering part of the mining machine may have a barrier which co-operates with said baffle or plate to limit the movement of spalling mineral towards the support. It will be appreciated that in this arrangement the barrier moves from support to support as the mining machine moves along the face or in to the excavation.

One particular embodiment of the invention will now be described, by way of example, with reference to the accompanying semi-diagrammatic drawings in which:

FIG. 1 shows a mine roof support in side elevation, and

FIG. 2 is a plan view of two such supports.

The support shown on the drawings comprises a base having mounted on it a pair of front side-by-side hydraulically extensible props 11 and a pair of rear sideby-side hydraulically extensible props 12. These props support on their upper parts a canopy 13. A cantilever roof-engaging member 14 is pivotally connected to the canopy at 15. A hydraulic ram 14a is provided for setting the member 14 to the roof. The cantilever roof engaging member 14 has slidably supported in it an extension bar 16 for supporting the forward area of the roof over a mineral mining machine which wins or extracts the coal, or other mineral, as it travels through the excavation between the mineral face F and a barrier 17. The barrier 17 may also serve as or include a section of rail for guiding the mineral mining machine.

Extension and retraction of the extension bar 16 may be effected by a hydraulic ram 16a having its cylinder connected to the member 14 and its piston connected to the extension bar (as shown in FIG. 1) or vice versa.

The base 10 of the support also incorporates a double-acting hydraulic ram 18 which is coupled to the barrier 17 as indicated at 19.

For the purpose of the present invention an antispalling plate or baffle 20 is pivotally connected to the forward end of the extension bar 16 as indicated at 21. The lower end of the baffle 20 is connected, at 22,'to a link 23 having its other end pivotally connected to the cantilever bar 14 as indicated at 24.

Mine roof supports, as above described, are operated as follows.

Prior to and during the passage of the mineral mining machine in front of a support, the baffle 20 thereof is in the position shown in full lines in the drawing. The baffle 20 thus acts to stop spalling mineral falling too far away from the mineral face and towards the support. The barrier 17 co-operates with the baffle plate 20 in this connection and for that reason may be provided with an extension 17a.

Following the passage of the mining machine past the support the extension bar 16 is advanced to provide support under the newly exposed roof. This causes the baffle 20, due to the link connection 23 to be moved into an inoperative or stowed position close under the extension bar as indicated in chain lines.

Following a complete transverse of the face or excavation the mining machine flits back along the face. The raising of the baffle plates 20, of the several sideby-side supports, provides a clear passage for the machine during this return passage along the face.

Before the machine commences a further cutting run along the face or into the excavation the rams 18 of the supports are extended in turn so as to advance the section of barrier 17, 17a, with which they are associated, towards the face. The rams are then retracted so as to advance the supports, in turn, up to the barrier 17 the props of the supports being temporarily lowered from the roof. The extension bars 16 of the supports are also retracted. It will be appreciated that when a support is being advanced in this way its associated barrier section 17 will be held stationary by attachment to a corresponding barrier section or sections of a neighbouring support or supports.

In a further embodiment of the invention supports, constructed and arranged to be operated, as described in the Specification of our British Application for Pat. No. 13973/72 filed on the Mar. 24 l972, have their extension bars provided with an anti-spalling baffle plate arrangement 20,23, as described above.

I claim:

1. A mine roof support having a first roof-engaging structure, a second roof-engaging structure slidable with respect to said first roof-engaging structure to form an extension thereof, pressure-fluid-operated ram means connected to said second roof-engaging structure for effecting sliding movement thereof with respect to said first roof-engaging structure and an antispalling baffle pivotally connected to said second roofengaging structure, a link arrangement pivotally connected at one end to said first roof-engaging structure and at its opposite end to a point on said baffle spaced from the pivotal connection of said baffle to said second roof-engaging structure whereby upon operation of said ram means to retract said second roof-engaging structure from extended state said baffle is pivoted into anoperative position in which it depends substantially vertically from said second roofengaging structure and upon operation of said ram means to extend said second roof-engaging structure said baffle is pivoted into a stowed position in which it lies along said second roof-engaging structure.

2. A mine roof support as claimed in claim 1 wherein the first roof-engaging structure comprises a canopy and a hollow cantilever member pivotally connected to the forward part of said canopy, and wherein the second roof-engaging structure is supported by said cantilever member for sliding movement therein.

3. A roof support as claimed in claim 1 and including a section of rail defining a track for a mineral mining machine in its passage along and into a mineral face, said section of rail including an upstanding barrier the upper edge of which cooperates with the lower edge of said baffle to limit the movement of spalling mineral.

4. A roof support as claimed in claim 3 including pressure-fluid-operated ram means connected between said section of rail and said support and operative to advance and retract said section of rail with respect to said first roof-engaging structure.

5. The combination with a mine roof support as claimed in claim 1 of a mineral mining machine having a mineral gathering part provided with a barrier which in the operating position of said machine with respect to said support co-operates with said baffle to limit the movement of spalling mineral. 

1. A mine roof support having a first roof-engaging structure, a second roof-engaging structure slidable with respect to said first roof-engaging structure to form an extension thereof, pressure-fluid-operated ram means connected to said second roofengaging structure for effecting sliding movement thereof with respect to said first roof-engaging structure and an antispalling baffle pivotally connected to said second roof-engaging structure, a link arrangement pivotally connected at one end to said first roof-engaging structure and at its opposite end to a point on said baffle spaced from the pivotal connection of said baffle to said second roof-engaging structure whereby upon operation of said ram means to retract said second roof-engaging structure from extended state said baffle is pivoted into an operative position in which it depends substantially vertically from said second roof-engaging structure and upon operation of said ram means to extend said second roof-engaging structure said baffle is pivoted into a stowed position in which it lies along said second roof-engaging structure.
 2. A mine roof support as claimed in claim 1 wherein the first roof-engaging structure comprises a canopy and a hollow cantilever member pivotally connected to the forward part of said canopy, and wherein the second roof-engaging structure is supported by said cantilever member for sliding movement therein.
 3. A roof support as claimed in claim 1 and including a section of rail defining a track for a mineral mining machine in its passage along and into a mineral face, said section of rail including an upstanding barrier the upper edge of which cooperates with the lower edge of said baffle to limit the movement of spalling mineral.
 4. A roof support as claimed in claim 3 including pressure-fluid-operated ram means connected between said section of rail and said support and operative to advance and retract said section of rail with respect to said first roof-engaging structure.
 5. The combination with a mine roof support as claimed in claim 1 of a mineral mining machine having a mineral gathering part provided with a barrier which in the operating position of said machine with respect to said support co-operates with said baffle to limit the movement of spalling mineral. 